Electrical water purification apparatus

ABSTRACT

An apparatus for water treatment, and in particular for electrical water purification in combination with a filtering apparatus for providing purified water for drinking and other application common in the home, farm or business. Metal, hydrogen and oxygen ions are introduced into water to be treated by using plasma fused iridium coated titanium electrodes and copper alloy electrodes. After ionizing the water to be purified, the water is then filtered in a filter tank which contains layers of various filtration media, including granular activated carbon.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 08/340,743filed Nov. 16, 1994, now U.S. Pat. No. 5,603,843, which is a 371 ofPCT/US97/00885, filed Jan. 17, 1997.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to water purification, and moreparticularly to electrical water purification apparatus and methods.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 5,007,994 to Snee, entitled "Water Purification System,"discloses a water purification system using a pair of carbon electrodesand a pair of copper electrodes submersed in the water to be filtered.When a potential is applied across these electrode pairs, the copperelectrodes release copper ions, while the carbon cathode produceshydrogen ions and the carbon anode produces oxygen ions. These ionsproduce a beneficial water treatment effect. Carbon electrodes are,however, subject to wear and have a limited life. Copper ions can resultin staining of surfaces coming into contact with the treated water. Thepresent invention provides improved electrode designs for both thecarbon and copper electrodes, and an improved water treatment system andmethod.

SUMMARY OF THE INVENTION

According to one exemplary embodiment of the invention, there isprovided a water filtration system and including a pair of electrodes atleast one of which comprises a plasma fused iridium coated titaniumelectrode used for the purpose of creating oxygen, hydrogen, andhydroxyl ions in the treatment of water. According to another aspect ofthe invention, a pair of electrodes formed of a copper, zinc andaluminum alloy provides copper, zinc and aluminum ions for the controlof algae and bacteria. The zinc ions also help reduce copper staining.The invention further provides a water filtration system and methodusing these electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of the filter tank showing the ionizationchambers and the pressure switch attached thereto;

FIG. 2 is a fragmentary side elevation view on a larger scale showingthe ionization chambers; and

FIG. 3 is a schematic illustration of the ionization chambers.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, and in particular to FIG. 1, the waterpurification system of the present invention is generally indicated byreference numeral 10. With the exception of electrode fabrication anddesign, and filtration media, the system is substantially identical tothat described in U.S. Pat. No. 5,007,994 to Snee, referred to above,the entire disclosure of which is hereby incorporated by reference. Themajor elements of the system are the filter tank 14 and the ionizationsystem 16, with the filter tank 14 having a control unit 12 mountedthereon.

Incoming water to be purified enters the water purification system 10through incoming water supply line 18. Water entering the system forpurification may be from either a local well, as in many ruralapplications, or it may be supplied by a municipal water system. Aswater to be purified is introduced into the water purification system10, it first encounters the ionization system 16, shown most clearly inFIG. 2. In the instance where the water to be purified is from a localwell or other water supply with an unusually high level of iron or othersimilar minerals such as manganese, a secondary ionization chamber 20will be provided through which the water will initially enter thesystem. Flow arrows represent the general direction of flow of the waterto be purified in the system. As may be seen in FIG. 2, water enters thesecondary ionization chamber 20 through the inlet port 22 of acommercially available modified T joint 24. The T joint 24 directs theflow of water into the secondary ionization chamber 20, which containstwo plasma fused iridium coated titanium electrodes 28 attached to thesecondary ionization chamber housing 26 by means of conductive screws30. The vapor coating of a titanium metal electrode with an alloy ofiridium metal allows for a bonding of iridium to the titaniumsubstructure to provide a surface coating of conductive material that isnot subject to normal breakdown and emission of metals into the water.Titanium by itself rapidly oxidizes and in doing so becomesnon-conductive. The iridium coating is not subject to such oxidizing andhas a long useful life. In the preferred embodiment, the electrodes 28are bars. Alternatively, one or both of electrodes 28 can be simplysolid carbon or carbon/graphite bars. After flowing through thesecondary ionization chamber 20 as depicted by the flow arrows, thewater exits the secondary ionization chamber 20 via the outlet port 32of the modified T joint 24.

Still referring to FIG. 2, in systems where water to be purified hasalready been treated by a municipal water system, or where the water hasalready circulated through the secondary ionization chamber 20, waterenters ionization chamber 34 through the inlet port 22 of a secondmodified T joint 24. As with the secondary ionization chamber 20, the Tjoint 24 directs the flow of water into ionization chamber 34, whichcontains two copper alloy electrodes 36 attached to the ionizationchamber housing 38 of ionization chamber 34 by means of conductivescrews 30. In the preferred embodiment, electrodes 36 are composed ofcopper with zinc and possibly aluminum, described in more detail below.Alternatively, the electrodes 36 can be made of pure 110 copper, in theform of solid copper bars. Alternatively, after flowing through thecopper electrode ionization chamber 38 as depicted by the flow arrows,the water exits the copper electrode ionization chamber 38 via theoutlet port 32 of the modified T joint 24.

The electrodes 28 and 36 are activated by means of a flow switch 40which alternatively can be implemented as a passive switch if required.As water flowing through the system is detected by the switch 40, acircuit therein is closed providing electrical power to the electrodes28 and 36 by means of a wire 41 connecting the conductive screws 30 withthe source of the electrical power, an ion controller located on theback of the control unit 12. The ion controller is representedschematically in FIG. 3 with reference numeral 42. This ion controller42 converts conventional AC power to DC, and reverses the direction ofthe DC current approximately every five minutes to minimize electrodewear. The electrical current supplied by the ion controller 42 resultsin a level of approximately 0.5 ppm (parts per million) of copper in thewater as supplied by the copper electrodes 36. The switch 40 may belocated either between the primary ionization chamber 34 and the filtertank 14, or, where high levels of corrosive contaminants are found inthe water to be purified, it may be located on the water line containingpurified water leaving the filter tank. In certain applications switch40 will not be used, as in where the supply of DC current is tied in tothe activation of a pump supplying water for the structure beingserviced.

After passing through the ionization system 16, water undergoingpurification enters the filter tank 14 via a filter tank inlet port 44.According to one exemplary embodiment, there are three layers, orregions, of filtration media in the filter tank 14. Referring to FIG. 1,the first and uppermost layer 46 comprises granular activated carbon(G.A.C.). This is the first layer of filtration media encountered by thewater being purified. The second layer of filtration media 48 preferablyof about equal proportion to the first layer, is comprised of manganesedioxide (Mg₂ O₃). The third and final layer of filtration media 50comprises gravel. In an alternative embodiment, oyster shells or someother calcite may be used as a pre-filter for pH increase. In thepreferred embodiment there are no membranes or other barriers dividingthe various regions of filtration media in the filter tank. These areunnecessary as the various layers maintain their relative positions dueto the effect of their relative densities and masses. Alternatively,another exemplary preferred embodiment of the invention provides thathydroxite is used as a substitute for manganese dioxide. Hydroxite is aspecial blend of insoluble natural minerals to filter and removecontaminants. As explained further below, hydroxite, sold under thebrand name Pyrolox™ for example, is a super oxidation media, with thehighest oxidation capabilities of any media on the market. It is a highpurity, natural mineral specialty processed to enhance and promote itsfunction as a high capacity media for water filtration.

After passing through the filtration media, the water undergoingtreatment or purification is drawn into the purified water distributor52 and drawn out of the tank, from which it departs through the filtertank outlet port, and goes on to enter the water system of the structurein which it is located.

The control unit 12 is activated manually or by an integral timer. Thetimer periodically activates the control unit 12, which initiates abackwash, or regeneration, cycle within the filter tank. The backwashcycle is required to remove any substances that have been filtered outof the purified water during purification which have been trapped in thelayers of filtration media. This is important because the backwash cycleserves to remove contaminants that have accumulated in the variouslayers of filtration media in the filter tank 14. If contaminants areallowed to build up, the filtration media will become ineffective,allowing contaminants to pass through the filter tank and into the watersystem. Backwash is accomplished automatically by forcing water down thedistributor 52 and then through the layers of filtration media in adirection opposite to that of the flow arrows shown in FIG. 1. Thebackwash fluid is then forced out of the system through a drainage valvewhich is linked directly to the sewer system by means of a small hose.During the backwash cycle, a valve in the control unit 12 is rinsed,thereby not allowing any of the backwash to be inadvertently forced intothe water supply of the system for which the water is being purified. Itis important that the backwash cycle be operated on a periodic basis.The automatic backwash is preferably programmable to operate daily oronly on preselected days up to once every twelve days. Preferably, thesystem also has a manual backwash option for city and well water withlow levels of silt and sediment and no problem with iron or manganese(backwashing gives added protection from possible bacteria and chemicalor sediment build-up). The system can also be provided with upflownon-backwash operation for purification of municipal treated water.

In operation, when water is drawn from the system being serviced by thewater purification system of the invention, as from a household faucet,water is thereby drawn through the water purification system. This flowof water is detected by the switch 40, and DC electrical current is thenprovided to the ionization chambers from the ion controller 42 locatedin the control unit 12. Where a secondary ionization chamber 20 has beeninstalled as part of the water purification system 10, the activation ofthe electrodes 28 causes the generation of hydrogen ions by the cathode54 and oxygen ions by the anode 56, as represented schematically in FIG.3. Likewise, the activation of the electrodes 36 causes the generationof hydrogen ions by the cathode 58 and oxygen and copper, zinc (andaluminum if present) ions by the anode 60 in the case where anode 60 isthe copper, zinc (and aluminum, if present) alloy, or copper ions onlyif the anode 60 is pure copper. The oxygen ions generated by the anodescombine with dissolved iron and manganese in the water to be purifiedwhich are, as the sulfur particles, later filtered and removed in thefilter tank. Likewise, the hydrogen ions help calcium bicarbonate ionshold onto their hydrogen atoms and not convert into calcium carbonateions (scale) when heated. This is beneficial because calcium carbonatetends to contribute to the scaling of water heaters, pipes and otherplumbing appliances. Further, "neutral" particles like silica or aluminatend to pick up a negative charge as they pass by the electrodes.Normally these particles help form hard scale by binding calcium andmagnesium carbonate together. However, the negative charges they pick upfrom the electrodes cause the particles to repel each other and preventthe binding effect. The copper ions created by the electrodes kill offalgae and bacteria, which are then removed from the water in the filtertank. Likewise, these copper ions also tend to strip the bondingproperties of the existing hard scale within pipes and fixtures, andthereby reduce the scale as it wears away over time. The zinc ions helpthe copper ions as a fungicide and algicide, and help displace copperions to reduce copper staining, as explained in more detail below.

After passing through the ionization system 16, the water to be purifiedenters the filter tank 14. In the filter tank 14, the water passesthrough the GAC layer 46, then the manganese dioxide layer 48, andfinally the gravel layer 50 or alternatively, through the mix of GAC,Hydroxite, and gravel. While passing through the granular activatedcarbon layer 46 or the Hydroxite, the water deposits chlorine, VOCs(volatile organic chemicals), and many other contaminants. This layer iseffective because most natural and man-made organic chemicals will befiltered from the water. By activated carbons ability to absorb andadsorb these chemicals. Activated carbon is also effective in removingradon gas from water. The manganese dioxide layer 48 is most effectivein the removal of iron particles. The gravel/calcite layer 50 serves tohelp maintain a neutral or higher pH balance for water that has beenpurified by the system, as well as helping to maintain a relatively highlevel of beneficial calcium bicarbonate, and a relatively low level ofcalcium carbonate, which leads to calcium hardness or scaling in pipesand plumbing appliances. Hydroxite is very similar to activated carbonin that it is highly porous with an extremely large surface area. Thehigh porosity allows hydroxite to address and effectively remove iron,manganese, hydrogen sulfide, arsenic, barium, lead, mercury and otherheavy metals and contaminants along with chlorine. Hydroxite isrelatively new for general water treatment but has been used forindustrial applications for years. Typical applications include metalremoval, taste and odor control, turbidity reduction, dechlorination andto extend GAC carbon bed life. Hydroxite works on the principle ofcatalytic oxygen reaction, which means it causes and promotes reactionsbut itself remains unchanged. This reaction is accomplished by theformation of oxygenated compounds, such as oxides of iron and manganese.Hydroxite promotes oxygenation whereby hydrogen sulfide, iron andmanganese are attracted to the media and held on the surface of theHydroxite until simple backwashing cleans the bed. No chemicalregeneration is required, nothing is imparted into the drinking waterand essentially unlimited capacity for removal of low level contaminantsis possible. Hydroxite works equally well in pH ranges of 6 to 9.However, if you have a pH of 6 or under, it would be helpful toneutralize the water to 7. The level of sulfur or iron does not affectthe performance. Manganese at high levels, with low pH, extra dwell timemay be needed. The higher the pH the better the manganese removal, i.e.,a 7 to 8 pH is ideal for manganese removal. The lower the pH the betterthe iron removal.

After filtering though these regions of the filter tank 4, the nowpurified water enters the water distributor 52, and is drawn into thewater system of the establishment or water use being serviced.

Since various water system may have specific needs or problems withwhich to deal in various applications, the water purification system 10may be varied in certain particulars, including the size of the filtertank 14 and the relative amounts of filtration media placed within thefilter tank 14. As noted above, electrodes 36 are preferably composed ofcopper with zinc and sometimes aluminum. Preferably, a copper and zincelectrode is 20-40% zinc and 60-80% copper. If aluminum is included, itis approximately 10%. When power in the form of low voltage directcurrent is applied to these electrodes they will emit metal ions ascopper ions (plus 2), zinc ions (plus 2); and, if present, aluminum ionsplus (3). The coppers primary function is as an algicide andbactericide. Copper in its pure ionic and uncombined form isapproximately five times more active and effective than copper in achemical form such as copper sulfate. Copper based algicides typicallyare celated or bound to other chemicals to minimize their potential forstaining surfaces the water is in contact with. Due to the stainingpotential of copper, particularly with concrete swimming pools, carefuluse and precautions are needed, water balance and pH are very important.Copper's staining is in the form of blue, bluish green, black or variousshades of grey. Zinc has been accepted and used for control of mildewand fungus. Mildew, when in a body of water, would be considered algae;therefore, zinc in effect is an algicide. Generally zinc is not acommonly used algicide. At present, based on testing conducted to date,zinc does not appear effective to control bacteria by itself. However,zinc in the make-up of the electrodes is to support the copper ions asan algicide, thus reducing the level of copper usage and reducingpotential staining. The secondary and more important function of zinc isin its ability to displace copper and prevent staining. Theelectronegativity of zinc is greater than copper and will displacecopper when oxidized or in the form of a stain. Aluminum is used as aflocking agent to cause other chemicals to come out of solution and tocause existing negatively charged contaminants to precipitate.

It is anticipated that various changes may be made in the size, shape,and construction of the water treatment system disclosed herein withoutdeparting from the spirit and scope of the invention as defined by thefollowing claims.

What is claimed is:
 1. A water treatment apparatus, comprising: anionization chamber containing two spaced apart ion-producing electrodesand having an inlet port and an outlet port, said inlet port beingconnected to an incoming water line for supplying water to be treated tosaid chamber, and said inlet port and said outlet port being so arrangedin separate, fluid flow communication with said chamber that water to betreated from said incoming water line will pass through said inlet portand around said ion-producing electrodes before flowing out of saidchamber through said outlet port; and at least one of said ion-producingelectrodes of said ionization chamber comprises plasma fused iridiumcoated titanium, the apparatus further comprising an ion controller,wherein one electrode acts as an original anode and the second electrodeacts as an original cathode, the electrodes being positioned in the samechamber so that untreated water may be passed over each of theelectrodes in a water treatment process, the ion controller beingconstructed and arranged to periodically reverse the direction of thecurrent to the electrodes and change the polarity of the electrodesduring a water treatment process so that the original anode becomes acathode and the original cathode becomes an anode, to minimize electrodewear.
 2. A water treatment apparatus according to claim 1 furtherincluding a filter tank containing a hydroxite filter media, the filtertank connected to the outlet port whereby said water to be purified fromsaid incoming water line passes through said ionization chamber beforeentering said filter tank, and then passes first through said hydroxitebeing discharged from said filter tank in a purified state.
 3. A watertreatment apparatus according to claim 1 further including another pairion producing electrodes at least one of which comprises an alloy ofcopper and zinc.
 4. A water treatment apparatus according to claim 3,wherein the at least one of the electrodes further comprises an aluminumalloy.
 5. A water treatment apparatus according to claim 1 for includinganother pair ion producing electrodes at least one of which is comprisesa plasma fused iridium coated titanium.
 6. A water treatment apparatusaccording to claim 1, wherein both of said ion-producing electrodes ofsaid ionization chamber comprise plasma fused iridium coated titanium.